The present invention relates generally to valves and, more specifically, to a flow rate control valve for use with fluids having suspended particles therein.
Valves for controlling the rate of flow of fluids are well known in the prior art and widely used in a huge variety of technical fields. Typically, a valve includes a housing having an inner passage with a valve seat extending therethrough and a valve member positioned within the passage. The valve member is selectively movable between a first position where the valve member fully contacts the valve seat in the inner passage in order to close the valve and completely interrupt the passage of any fluid, and a second position where the valve member is positioned a distance away from the valve seat in the inner passage in order to open the valve and allow the passage of fluid through said valve. The above description corresponds to a simple embodiment of a flow rate control valve. Several more sophisticated models of these valves are known in the art, including valves with mechanical, hydraulic, electric and/or electronic driving means, or any combination thereof, to control the movement of the valve member to automatically open and close the valve.
A typical use of the flow rate control valves is in the agriculture, to control spraying of agrochemical or agricultural fluids. The flow rate control valves presently known in the art, however, when used to control the spraying of agrochemical or agricultural fluids, have several drawbacks that impair their use. Basically, these drawbacks are related to the fact that the agrochemical and/or agricultural fluids typically include a solution having a considerable number of particles suspended therein, which particles may attach and damage the driving means. As a result, the valves work poorly due to the fact that its driving means operate in a highly contaminated environment, the valve does not closes properly due to the buildup of debris in the valve seat that does not allow for the proper seating of the valve member, or the jamming of the driving means under the attack of the contaminating agents occurs.